Radiative Processes in Hot High-Density Plasmas

热高密度等离子体中的辐射过程

基本信息

批准号：
61580008
负责人：
TOTSUJI Hiroo
金额：
$ 1.22万
依托单位：
Okayama University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1987
项目状态：
已结题

项目摘要

In hot high-density plasmas realized in the inertial confinement fusion, radiative processes make important contributions to the energy transport. In these high-density plasmas, the cross sections of such processes may be affected by correlations between charged particles. We have investigated the free-free (bremsstrahlung) and teh free-bound transitions which are dominant in laser fusion plasmas.1. The free-free transition probability is signigicantly reduced by the ion correlation in some cases, depending on the degree of electronic degeneracy, the strength of ionic coupling, and the frequency. For ionic mixtures, this reduction can be expressed by the result for ions of one species by a simple scaling.2. For the free-bound transition, fluctuating electric fields of surrounding ions increase the probability whether ions are correlated or not, while correlations between ions decrease it. The coross section is thus enhanced or reduced when ion correlation is weak or strong.3. The effect of electron-ion correlation can be regarded as that of screening of ionic charges. When the screening is described by the linear response, the direct effect on ionic potentials and the indirect effect to weaken ion correlations almost cancel with each other. When the ionic charge is large and the screening is nonlinear, the former prevails and the cross section is reduced.4. Unified treatment of the free-free and free-bound processes as well as the screening effect on the free-bound process is left for future studies.

在惯性限制融合中实现的热密度等离子体中，辐射过程对能量传输做出了重要贡献。在这些高密度等离子体中，此类过程的横截面可能会受到带电粒子之间的相关性的影响。我们已经调查了无用的（Bremsstrahlung）和Teh自由结合的过渡，这些过渡在激光融合等离子体中占主导地位1。在某些情况下，离子相关性明显降低了自由过渡的概率，具体取决于电子退化的程度，离子耦合的强度和频率。对于离子混合物，可以通过简单的缩放来表达这种还原的结果。2。对于自由结合的过渡，周围离子的电场波动会增加离子是否相关的概率，而离子之间的相关性会降低它。因此，当离子相关性较弱或较强时，珊瑚部分会增强或减少3。电子离子相关性的效果可以视为离子电荷筛选的影响。当通过线性响应描述筛选时，对离子电位的直接影响和弱化离子相关性的间接效应几乎相互抵消。当离子电荷较大并且筛选为非线性时，前者占上风，横截面降低。4。无统一的免费和自由结合过程的处理以及对自由结合过程的筛查效果，以供将来的研究。